The invention relates to administering devices and methods. More particularly, it relates to an administering apparatus or device with a dosage display which allows a product dosage to be selected, and to a method of providing a dosage display. The administering device of the present invention may be used in medical, veterinary, therapeutic, diagnostic, pharmaceutical and/or cosmetic applications. One preferred example of administering apparatus in accordance with the present invention is injection apparatus, including injection pens. Other examples of administering apparatus according to the invention can include inhalation apparatus or apparatus for administering liquid nutrients in doses.
Administering apparatus which allow a dosage to be selected naturally have a dosage display in order to indicate the selected product dosage to be administered to the user of the apparatus. A reliable dosage display is essential for selecting and administering the desired product dosage.
In the injection apparatus known from U.S. Pat. No. 6,228,067, an optical dosage display is provided between two casing sleeves which can be rotated relative to each other, for selecting a dosage. The two casing sleeves overlap each other. A dosage scale is printed onto the inner casing sleeve in the overlapping area, the scale consisting of a sequence of dosage numbers representing dosage units. The outer casing sleeve in the overlapping area is transparent in the area of the dosage scale, by comprising an opening there which serves as a viewing window. To select a dosage, the two casing sleeves are rotated relative to each other. The injection apparatus further comprises a dosing sleeve arranged in the overlapping area between the two casing sleeves which is axially moved relative to the casing sleeves, to select the dosage. The dosing sleeve likewise comprises a viewing window for reading the dosage scale. The dosage scale is read through the two superimposed viewing windows of the dosing sleeve and the outer casing sleeve.
The selected product dosage can indeed be reliably read with the aid of this dosage scale. However, the user then only knows that he has selected the desired dosage. It remains uncertain whether the entire dosage or only a part of it, for example because evacuation of a product reservoir is already in progress, can be administered in the next injection.